import random

def gen_case(length):
    # 生成长度为length的数字字符串，数字范围1-9
    return ''.join(str(random.randint(1, 9)) for _ in range(length))

def generate_cases():
    with open('cases.txt', 'w') as f:
        for n in range(10, 1001, 10):
            s = ''.join(str(random.randint(1, 9)) for _ in range(n))
            f.write(s + '\n')

if __name__ == "__main__":
    generate_cases() 